1. Field of the Invention
The invention relates in general to a controller, and more particularly to a controller applied in a light emitting diode (LED) driver.
2. Description of the Related Art
With the technology changes within each passing day, light emitting diode (LED) driver has been developed for enhancing people's living. In a practical case, LED has been applied as backlight source of a flat display. Generally, boost converters are employed in a LED backlight module for providing driving voltages in response to dimming control signals, so as to drive LED modules. For example, the dimming control signals are pulse width modulation (PWM) signals and the boost converters work in the duty cycle of the PWM signals, so as to accordingly provide the driving voltages.
In practical situation, however, the driving voltages provided by the boost converters are unstable due to the short duty cycle of the dimming signals. Thus, the LED modules are also affected and fail to provide light with stable brightness, resulted in flicker of the flat display. Thus, how to provide a LED driver capable of supplying stable driving voltages has become a prominent goal for the industries.